Pressure feed carburetor



-0ct. 31', 1939. J. HEwn'soN PRESSURE FEED CARBURETOR Filed April 22,1937 2 Sheets-Sheet 2 y 3mm/vbo@ close/viz Hew'i eff Patented Oct. 31,1939 UNITED STATES PATENT OFFICE PRESSURE FEED CARBUBETOR JosephHewitson, Kalispell, Mont.

buretor, and an object is to improve the construction of carburetordisclosed in Letters Patent issued to me on February 16, 1937, No.2,070,- 598, for improvements in Pressure feed carburetors.

Additional objects are to provide novel means wherein the feed of thefuel under pressureis thermostatically controlled and particularly bymeans located in a chamber or the like through which exhaust gases, orair heated from the engine, travels, or other heating means provided.

It is also aimed to provide a novel fan mechanism for increasingturbulence and supercharging in a mixing chamber, and which fan isoperable by a turbine driven by the said exhaust or other heatingmedium.

A further object is to provide novel `means for more eilcientlypreheating the fuel and a novel auxiliary air valve means which iscontrolled by the load change and the resultant throttle movement thatchanges the intensity of the vacuum in the engine manifold.

The more specific objects and advantages will become apparent from aconsideration of the description following taken in connection withaccompanying drawings illustrating an operative embodiment. Y

In said drawings:

Figure 1 is a plan view of the improved pressure feed carburetor;

Figure 2 is a vertical sectional view taken substantially on the planeof line 2-2 of Figure 1;

Figure 3 is a horizontal sectional view taken substantially on the planeof line 3-3vof Figure 2;

Figure 4 is a vertical sectional view taken on the plane of line 4-4 ofFigure 3;

Figure 5 is a horizontal section taken on the plane of line 5-5 ofFigure 2;

Figure 6 is a detail section taken on the plane of line 6-6 of Figure1,`and I Figure 7 is a diagrammatic View of the detai of the structureof Figure 5.

Referring specifically to the drawings wherein like reference charactersdesignate like or similar parts, the carburetor comprises inner landouter castings or cylinders III and II, having spacing rings I2 and I3,therebetween, 'at the top and bottom, and a plate I4 also extends acrossthe top of the carburetor and is secured to said cylinders and ring I2while at the bottom, a pipe or conduit member I5 is'rigidly ordetachably secured to the said cylinders I0 and II and ring I3, asthrough the medium of a flange I6. The usual throttle-valve I1 ispivotally mounted on 1937, Serial N0l 138,443

a spindle I8 journaled diametrically of the conduit section I5 `and suchsection is attached mediately or immediately to the intake manifold ofthe internal combustion engine in connection with which the carburetoris used. Centrally of 3 the plate I4, an air inlet port I9 is provided,which is adapted to be closed or opened to variable degrees as willlater be explained.

Attached to the outer cylinder II is a block 2l. This block, if desired,may be made integral with `1l) such cylinder. The block has a fuel inletpassage 22 connected with a pipe 23, in communication with any suitablesource of fuel supply, for instance gasoline. Passage 22 has a lateralextension 24 provided with a .valve seat 25 with ll which a main or fuelcontrol needle valve 26 slidably co-acts. Said passage 22 beyond theseat communicates with a fuel supply pipe 26', preferably U-shape orotherwise'extended in the space between cylinders Ill'and I I andhereafter go referred to as a heating chamber. Pipe 26' terminates in anenlarged portion or outlet nozzlell, preferably disposed diametricallyacross a superheating or mixing chamber 23, such nozzle preferablyhaving a multiplicity of outlet orifices 3l u diametrically arranged.

In the block 2l aforesaid, branches 32 and 33 are provided incommunication with the passage 22. A needle valve 34, for idlingadjustment, is screw threaded to the block at 35 and co-acts .u withaseat 36 at the junction of the passages 32 and 33. From the passage 33,a tube 3I'leads, extending downwardly through the heating chamber 21 andcommunicating with a passage 38 extending through ring I3 and conduitsection I5 and opening into the interior of the latter, adjacent thethrottle-valve Il.

Vacuum operated means is adapted to bleed air into the main fuel pipe orpassage 21 and also into the idling fuel pipeor passage 31. To this end,as best shown in Figure 5, a passage 39 is arranged in communicationwith the passage k311i and a passage or port 40 is arranged incommunication with passageway 24. A plate or ring 4I secured in thepassage 39 has a port 42 there- 45 through normally closed by a valve 43under urgency of a spring 44,r which valve 43, however, is adapted to beopened by the suction or vacuum within the engine. Passage 40 is adaptedto control a valve seat at 45 by a valve member 46 slidable through adisk 41 and having communication with the atmosphere and with thepassage 4U through the medium of ports at 48. Port 42 also communicateswith the atmosphere. A lever 4911s pivoted at 5I to a stud 52 on theblock 2| 55 and such lever at opposite ends through the medium of pinsand elongated slots is operatively connected at 53 to the needle valve46 and at 54 to a projection 55 on the poppet valve 43. Y

The heating chamber 21 is adapted to communicate with the exhaust lineof the internal combustion engine and to receive the exhaust gasesdirectly therein at the conduit or port 56. However, in lieu of theexhaust gases, heated air from any desired source and preferably frommeans on or adjacent to the exhaust manifold of the engine may be usedinstead of such exhaust. Said pipe 56 has two branches communieatingwith the chamber 21 as at 51 and 58, the former serving to better heatthe mixing chamber. It will be apparent that the heating may be done byan electric heating coil within the heating chamber supplied from abattery or other source to serve the same purpose.

A stationary body 59 is disposed centrally of the inner cylinder I9 anda vertical shaft 60 is journaled therein having a fan at its top as at6I for turbulence. Body 59 has a space 62 therein in which an impeller63 is disposed and which is fastened to the shaft 6U. A tube or conduit64 is mounted in the cylinder walls I0 and II and communicates with thebranch 58 and with the space 62, to conduct exhaust or other fluid tospace 62 land operates impeller 63 through impact therewith, the mediumescaping from the space 62 through a pipe 65 mounted in the wall ofcylinder I8 and in the body and communicating with the heat chamber 21and an outlet or discharge pipe 66 leads from the wall II, in line withthe said pipe 65. A suitable lubricator means may be provided at 61 tofacilitate the lubrication of shaft 60 through the medium of a pipe 68leading through the wall of cylinders I0 and II and through the body 59.

Disposed in the heating chamber 21 is a rod 69 adjustably fastened at 18to the ring I2. Parallel with the rod 69 is a rod 1| which is slidablethrough the said ring I2 and the rods 69 and 1| are selectivelyconnected together through pivotal connection with a lever 12, pivotedat 13 to the cylinder wall II. Rod 1| extends through a lever 14 at anopening 15 and has adjustable engagement with such lever by means of anut 16 threaded on the rod 1I.

The lever 14 is pivoted at 11 to the plate I4. A contractile coll spring18 is adjustably anchored at 19 to the casing Il and is connected to alateral arm 80 of the lever 14. A lever 8| extends from the valve 20 andis pivoted at 82 to a bracket or the like 83 secured to plate I4. Lug 84on lever 8| engages the lever 14 and lever 8|, at its outer end has acontractile coil spring secured to it, and through the medium of a screwthreaded eyelet member 86, is adjustably secured to the block 2|. Lever8| has an elongated slot at 81 in which a part 88 on the heater valve26, is loosely connected.

The rods 69 and 1| are of a suitable metal which will expand when heatedby the exhaust gases or other heating medium passing through the chamber21, a`s for instance copper, brass or aluminum. Lever 14 is made of thesame materials as said rods 69 and 1I. It will be understood, that nolimitation is to be implied since any equivalent thermostatlc means maybe substituted for one or all of the said parts 69, 1| and 14. Normally,the parts 69, 1| and 14 being cold or at normal temperature, the mainfuel control valve 26 will be open to the maximum extent.

As the valve 26 is normally open to the maximum extent, when startingthe motor rich fuel will be drawn from the pipe 23 past both Aof thevalves 34 and 26, escaping from the former at passage 38 adjacent thethrottle valve I1 and escaping from the latter through the orices 28into the mixing chamber or upper part of the cylinder I0, the necessaryturbulence being created by operation of the fan 6I in coaction with theorirlces 38. The port i8 will be open and under the control of the valve28 according to temperature conditions, to admit air into the mixingchamber for admixture with the fuel escaping through jets 30. Theexhaust gases pass through the branch 58, pipe 64 and operate theturbine 63 and then escape through pipe 66 into the heating chamber 21and exhaust gases will also pass into said heating chamber 21 throughthe upper branch 51, serving to better heat such mixing chamber for moreefficient vaporization.

The exhaust gases will efficiently preheat the fuel due to the fact thatthe pipes 26 and 31 are disposed in the chamber 21 and thus in the pathof such exhaust gases to escape into the atmosphere through the outlet66. As soon as the thermostatic means 69, 1| and 14 are heated by theexhaust gases, the engine will be capable of idling on the fuel passingthrough the passage 31, at which time, the thermostatic means expand andclose the valve 26. The rich mixture will pass both valves 34 and 26 soas to be available for starting purposes only. The lever means 12 and 14may be varied as desired to multiply 'the expansion of the thermostaticelements as far as desired.

It will be realized that the said high speed needle valve 26 through theconnections described, will be controlled by the operation of the valve20 controlling the admission of air into the mixing chamber, such valve20 being normally urged to its seat by the spring 85.

The impeller 63 rather than being operated by exhaust gases orequivalent medium, may be operated in any suitable manner as by a chargefrom the cylinders of the motor direct, by an exploding jet or bycompressed air furnished by various means.

Attention is called to the fact that the vacuum operated poppet valve 43facilitates the bleeding of air into both the high speed and the idlingjets. The decrease in vacuum in the intake manifold of the engine as thethrottle I1 is opened allows spring 44 to close the valve 43 and applyall the vacuum to the fuel but as the vacuum again builds up under astationary throttle, the valve is again drawn open and releases thevacuum on the jets by allowing air to enter with the fuel.

'Ihe various parts are preferably adjustable and particularly the poppetvacuum control valve 43 through the medium of tensioning of spring 44,adjustment of the fulcrum at 49, the high speed needle valve and of theexpansion control system.

As best shown in Figure 4, I may employ an auxiliary air valve 90coacting with a seat 9| in an elbow conduit 92 communicating with theatmosphere and with the mixing chamber or interior of the cylinder I0.Valve 90 is carried by a slidable stem 93 urged upwardly by a spring 84abutting an adjustable nut 95 on the rod 93 and also abutting a spider96 at the upper end of the conduit 92. Rod 93 by means of a link 91 isdetachably and adjustably connected to a rod 98 extending from a piston99 operating in vention.

a cylinder having an elbow pipe Illl in communication with the conduitsection I and accordingly subject to the suction of the engine. A ventopening l-Il2 is provided in the top wall of the cylinder |00. Said airvalve 9| is opened when the vacuum in the manifold is suiiicient toovercome the spring tension on the spring means for closing the valve,this tension being adjustable as desired, the greater vacuum exerting astrong pull on the piston 99 through pipe I 0|; When said throttle isopen for accelerating or for more power, the vacuum in the manifolddrops and said piston returns, thus closing the valve 90 and allowing aricher mixture. Adjustment of the spring 94 at the nut 95, the pointWhere the valve 90 operates, may be changed according to differentconditions. At higher engine speeds, the vacuum in the manifold and inthe carburetor combined hold the valve 90 open, relieving the vacuum orsuction on the main fuel supply.

Various changes may be resorted to provided they fall within the spiritand scope of the in- I claim as my invention:

l. A carburetor of the class described having a mixing chamber, a portfor the intake of air to said mixing chamber, a valve member controllingsaid port, a conduit for the supply of fuel to the mixing chamber, avalve in said conduit, a lever connected to the valve and to the valvemember, a thermostatic lever engaged by the last mentioned lever, athermostatic rod operatively connected to the second mentioned lever, athermostatic rod anchored to the carburetor, and multiplying lever meansconnecting said rods.

2. A carburetor of the class described having a mixing chamber, a portfor the intake of air to said mixing chamber, a valve member controllingsaid port, a conduit for the supply of fuel to the mixing chamber, avalve in said conduit, a lever connected to the valve and to the valvemember, a thermostatic lever engaged by the last mentloned lever, athermostatic rod operatively connected to the second mentioned lever, athermostatic rod anchored to the carburetor, multiplying lever meansconnecting said rods, means providing a chamber into which said rodsextend,

and means for the admission of exhaust gases into said last mentionedchamber.

3. A carburetor of the class described having a mixing chamber, a portfor the intake of air to said mixing chamber, a valve member controllingsaid port, a conduit for the supply of fuel to the mixing chamber, avalve in said conduit, a lever connected to the valve and to the valvemember, a thermostatic lever engaged by the last mentioned lever, athermostatic rod operatively connected to the second mentioned lever, athermostatic rod anchored to the carburetor, multiplying lever meansconnecting said rods, means providing a chamber into which said rodsextend, means for the admission of exhaust gases into said lastmentioned chamber, a conduit in the mixing chamber having outletorifices for the fuel, a fan operable adjacent said orices, a turbine toactuate said fan, and means to supply exhaust gases to operate saidturbine.

4. A carburetor of the class described having a conduit for the passageof fuel into the same, a branch passage leading from said firstmentioned passage for idling adjustment, a valve controlling the branchpassage, thermostatic means operable to close the first mentioned valveand passage through heat of the engine, and means operable to bleed airinto the ilrst mentioned conduit and into the branch passage operable byvacuum in the engine.

5. A carburetor of the class described having a conduit for the passageof fuel into the same, a branch passage leading from said conduit ioridling purposes, a valve controlling the branch passage, thermostaticmeans operable to close the valve and conduit through heat of theengine, and means operable to bleed air into the rst mentioned conduitand into the branch passage operable by vacuum in the engine, includingvalves coacting with ports associated with each passage, one of saidvalves being a vacuum operated valve, a lever connected to the lastmentioned valve, and means pivotally mounting the lever.

JOSEPH HEWITSON.-

